Project 2 proposes to develop fluorescent, PET, and SPECT imaging agents targeted to the enzyme, cyclooxygenase (COX)-2. COX-2 is highly expressed in many solid tumors but not in most untransformed epithelial tissues. Thus, it makes an attractive target for molecular imaging. All of the reviewers of this project agreed that there is a strong rationale for targeting COX-2. They also felt that the research was innovative because, although other laboratories have attempted to develop COX-targeted imaging agents, none have succeeded. Despite the high enthusiasm for the concept, the reviewers were critical of certain aspects of the proposed research plan.